Hemodynamics changes and collateral flow in patients with middle cerebral artery serious stenosis

Objective To investigate the hemodynamic changes and compensation of collateral flow in patients with serious middle cerebral artery(MCA)stenosis or occlusion,and to approach the relationship of collateral flow with the patients’ neurologic impairment. Methods Through the examination of transcranial doppler(TCD),the ratio of bilateral anterior cerebral artery (RVACA) flow velocity and the ratio of the bilateral posterior cerebral artery (RVPCA) flow velocity were calculated in patients with the middle cerebral artery serious stenosis or ocllusion,and compared with the healthy controls. Results 38 patients with single middle cerebral artery stenosis or occlusion were studied. The patient group had compensative acceleration of the ACA and PCA velocity. RVACA in the patient group was significantly higher than ratios of controls﹙P0.01﹚;RVACA in the patient. with stem and cortex infarction was higher than those of controls. There was an negative correlation between the RVACA and the NIHSS in patient group. and the same for RVPCA. Conclusion The opening of leptomeningeal anastomoses vessel is the important way of collateral circulation in cases of serious stenosis or occlusion of MCA,and the collateral flow between MCA and ACA is dominant. There is a inverse correlation between the RVACA/RVPCA and the NIHSS.